Retrieval devices and related methods of use

ABSTRACT

According to an embodiment of the present disclosure, a retrieval device may include a distally located end effector movable between a contracted state and an expanded state. The end effector may include a plurality of support members each including a passage. The end effector may also include a plurality of movable members. A first movable member may include a first portion extending into a first passage of the support member passages. The retrieval device may also include a proximally located handle assembly including a longitudinal actuator and a twisting actuator coupled to the plurality of movable members. The longitudinal actuator and twisting actuator may be configured to longitudinally move and twist the movable members without longitudinally moving and twisting the support members.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority from U.S. ProvisionalApplication No. 61/923,446, filed on Jan. 3, 2014, which is incorporatedby reference herein in its entirety.

TECHNICAL FIELD

Various embodiments of the present disclosure relate generally toretrieval devices and related systems and methods. More specifically,the present disclosure relates to devices, systems, and methods forretrieving objects within a patient.

BACKGROUND

Retrieval devices are often used to remove organic material (e.g., bloodclots, tissue, and biological concretions such as urinary, biliary, andpancreatic stones) and inorganic material (e.g., components of a medicaldevice or other foreign matter), which may obstruct or otherwise bepresent within a patient's body cavities or passages. For example,concretions can develop in certain parts of the body, such as in thekidneys, pancreas, ureter, and gallbladder. Minimally invasive medicalprocedures are used to remove these concretions through naturalorifices, or through an incision, such as during a percutaneousnephrolithotomy (“PNCL”) procedure. Further, lithotripsy andureteroscopy, for example, are used to treat urinary calculi (e.g.,kidney stones) in the ureter of a patient.

Retrieval devices may include end effectors for manipulating objects. Anexemplary end effector may have a plurality of arms that support a frontloop that forms when the end effector is opened. The size of the frontloop may limit the size of an object that can be captured, repositioned,and/or released from the end effector. For some procedures, there may bea need to increase the size of a front loop of an end effector tofacilitate the capturing, repositioning, and/or releasing of largerobjects. It may also be desirable to have an end effector close backdown to a low-profile state to facilitate insertion and withdrawal ofthe end effector into and from a target area, and/or to capture,reposition, and/or release smaller objects. Thus, there remains a needfor retrieval devices with improved capabilities.

SUMMARY

Embodiments of the present disclosure relate to, among other things,retrieval devices and related systems and methods. Each of theembodiments disclosed herein may include one or more of the featuresdescribed in connection with any of the other disclosed embodiments.

In one embodiment of the present disclosure, a retrieval device mayinclude a distally located end effector movable between a contractedstate and an expanded state. The end effector may include a plurality ofsupport members each including a passage. The end effector may alsoinclude a plurality of movable members. A first movable member mayinclude a first portion extending into a first passage of the supportmember passages. The retrieval device may also include a proximallylocated handle assembly including a longitudinal actuator and a twistingactuator coupled to the plurality of movable members. The longitudinalactuator and twisting actuator may be configured to longitudinally moveand twist the movable members without longitudinally moving and twistingthe support members.

Embodiments of the retrieval device may include one or more of thefollowing features: a second portion of the first movable member mayextend out of the first passage and into a second passage of the supportmember passages; the first movable member and a pair of adjacent supportmembers may form an end effector loop; the longitudinal actuator and thetwisting actuator may include a common actuator member for causinglongitudinal moving and twisting of the movable members; a portion ofone of the movable members may twist around a portion of another of themovable members; and a portion of each of the movable members may followa helical path.

In another embodiment of the present disclosure, a retrieval device mayinclude a distally located end effector movable between a contractedstate and an expanded state. The end effector may include a plurality ofsupport members each including a passage. The end effector may alsoinclude a plurality of movable members at least partially received inthe passages. In the expanded state the movable members may be displacedlongitudinally and twisted relative to the contracted state.

Embodiments of the retrieval device may include one or more of thefollowing features: each of the movable members may include a proximalportion and a distal portion, wherein at least part of the proximalportion may be rotatable relative to at least part of the distal portionto generate torsion in the movable member when the movable member istwisted, and the movable members may be movable longitudinally relativeto the support members; the torsion in the movable members may bias thedistal portions of the movable members towards bent configurations; asheath may be configured to receive the support members and the movablemembers, wherein each of the movable members may extend radiallyoutwardly from a longitudinal axis of the retrieval device when in thebent configuration; a proximally located handle assembly may beconfigured to twist the movable members and move the movable memberslongitudinally relative to the support members; the handle assembly maybe configured to rotate the movable members while moving the movablemembers longitudinally; the support members and the movable members mayform a plurality of loops; and the plurality of loops may include adistal front loop and a plurality of proximal side loops.

In another embodiment of the present disclosure, a method for retrievingan object from a target area may include positioning a distally locatedend effector of a retrieval device at the target area with the distallylocated end effector in a contracted state. The end effector may includea plurality of support members each including a passage. The endeffector may also include a plurality of movable members extending intothe support member passages. The method may also include expanding theend effector by longitudinally extending and twisting the movablemembers without longitudinally extending and twisting the supportmembers, to allow the object to enter the end effector.

Embodiments of the method may include one or more of the followingfeatures: the movable members may be twisted before being longitudinallyextended; the movable members may be twisted after being longitudinallyextended; the movable members may be twisted while being longitudinallyextended; contracting the end effector by longitudinally retracting theend effector; and contracting the end effector by untwisting the movablemembers.

It may be understood that both the foregoing general description and thefollowing detailed description are exemplary and explanatory only andare not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate exemplary embodiments of thepresent disclosure and together with the description, serve to explainthe principles of the disclosure.

FIG. 1 is a side view of a retrieval device including an end effector ina retracted and contracted state, in accordance with embodiments of thepresent disclosure.

FIG. 2 is a cross-sectional view of the retrieval device of FIG. 1, inaccordance with embodiments of the present disclosure.

FIG. 3 is a distal end view of the retrieval device of FIG. 1, inaccordance with embodiments of the present disclosure.

FIG. 4 is a perspective view of the retrieval device of FIG. 1 in anextended and expanded state, in accordance with embodiments of thepresent disclosure.

FIG. 5 is a distal end view of the retrieval device of FIG. 1 in theextended and expanded state, in accordance with embodiments of thepresent disclosure.

FIG. 6 is a distal end view of the retrieval device of FIG. 1 in anotherextended and expanded state, in accordance with embodiments of thepresent disclosure.

FIG. 7 is a perspective view of a portion of the retrieval device ofFIG. 1, in accordance with embodiments of the present disclosure.

FIG. 8A is a perspective view of a handle assembly of the retrievaldevice of FIG. 1, in accordance with embodiments of the presentdisclosure.

FIG. 8B is a side view of the handle assembly of FIG. 8A, in accordancewith embodiments of the present disclosure.

FIG. 8C is a side view of a holding mechanism of the handle assembly ofFIG. 8A, in accordance with embodiments of the present disclosure.

FIG. 8D is a side view of an actuation assembly of the handle assemblyof FIG. 8A, in accordance with embodiments of the present disclosure.

FIG. 9 is a perspective view of an alternative handle assembly of theretrieval device of FIG. 1, in accordance with embodiments of thepresent disclosure.

FIG. 10 is a perspective view of an alternative handle assembly of theretrieval device of FIG. 1, in accordance with embodiments of thepresent disclosure.

DETAILED DESCRIPTION Overview

The present disclosure is drawn to retrieval devices and related systemsand methods. Reference will now be made in detail to embodiments of thepresent disclosure, examples of which are illustrated in theaccompanying drawings. Wherever possible, the same reference numberswill be used throughout the drawings to refer to the same or like parts.The term “distal” refers to a portion farthest away from a user whenintroducing a device into a patient. By contrast, the term “proximal”refers to a portion closest to the user when placing the device into thepatient.

Exemplary Embodiments

FIGS. 1-3 show portions of a retrieval device 10. The retrieval device10 may include an outer sheath 12. The outer sheath 12 may include alumen 14 extending longitudinally through the outer sheath 12. The outersheath 12 may be, for example, a hollow tube of about 1.9 French,although the dimensions may differ based on the type of procedure beingperformed with the retrieval device 10. The outer sheath 12 may be madeof a polymer material or combination of materials. A proximal portion ofthe outer sheath 12 may be made of a different material than a distalportion of the outer sheath 12. For example, the distal portion of theouter sheath 12 may be made of a material that is more flexible than thematerial of the proximal portion of the outer sheath 12.

The retrieval device 10 may also include a drive member 16. The drivemember 16 may extend through the lumen 14. The drive member 16 may beelongated, and may include, for example, a wire, braid, shaft, and orany other suitable drive member configured to transfer translationaland/or rotational forces from its proximal end to its distal end. Thedrive member 16 may have any suitable cross-sectional shape, includingcylindrical, elliptical, polygonal, and/or irregular. The drive member16 may be made of metals, polymers, or a combination of materials. It isalso contemplated that the drive member 16 may have a diameter ofapproximately 0.0125 inches. The drive member 16 may have otherdiameters, however, depending on the type of procedure being performedwith the retrieval device 10.

The retrieval device 10 may also include a first movable member 18, asecond movable member 20, and a third movable member 22. The firstmovable member 18 may include a first leg 18 a, a reverse or U-shapedbend 18 b, and a second leg 18 c. The second movable member 20 mayinclude a first leg 20 a, a reverse or U-shaped bend 20 b, and a secondleg 20 c. The third movable member 22 may include a first leg 22 a, areverse or U-shaped bend 22 b, and a second leg 22 c. While threemovable members 18, 20, and 22 are shown, one or more additional movablemembers may also be included.

Each of the movable members 18, 20, and 22 may be formed of any suitablematerial including, but not limited to, metals, polymers, or acombination of materials. For example, one or more of the movablemembers 18, 20, and 22 may be formed with a shape memory material, suchas Nitinol, and may be treated to possess an internal bias causing oneor more of the movable members 18, 20, and 22 to move radially outwardlyaway from the longitudinal axis of the outer sheath 12 in the absence ofa constraining force. One or more of the movable members 18, 20, and 22may be a wire having a diameter of about 0.003 inches, although othersuitable diameters may alternatively be utilized.

Each of the movable members 18, 20, and 22 may have any suitablecross-sectional shape, including cylindrical, elliptical, polygonal,and/or irregular. One or more of the movable members 18, 20, and 22 mayinclude a portion flattened, machined, extruded, drawn, and/or etchedinto a different profile than a remaining portion. One or more of themovable members 18, 20, and 22 may be slotted to allow deflection ordirectional bending. The exterior surfaces of one or more of the movablemembers 18, 20, and 22 may be roughened, notched, slotted, etched,sand-blasted, or otherwise modified to provide a better grippingsurface.

The movable members 18, 20, and 22 may be attached to the drive member16. For example, proximal ends of the first legs 18 a, 20 a, and 22 amay be attached to the distal end of the drive member 16. The attachmentmay be provided by one or more of a splice joint, adhesives, melting,welding, crimping, and/or any other suitable attachment mechanism.

It is also contemplated that a sleeve 24 may be placed over the proximalportions of the first legs 18 a, 20 a, and 22 a, and the distal portionof the drive member 16. The sleeve 24 may be made of apolytetrafluoroethylene like TEFLON. The sleeve 24 may be heatshrinkable onto the first legs 18 a, 20 a, and 22 a, and the drivemember 16. The sleeve 24 may have a length of about 11.5 cm, but itshould be understood that the length and other sleeve dimensions mayvary based on the type of procedure being performed with the retrievaldevice 10. The sleeve 24 may help gather the first legs 18 a, 20 a, and22 a, so the gathered portions may not spread radially outwardly whenpushed distally by the drive member 16, giving the gathered portionsadded strength. The proximal portions of each of the first legs 18 a, 20a, and 22 a may contact the proximal portions of the other first legs.Longitudinal axes of the proximal portions of the first legs 18 a, 20 a,and 22 a may be substantially parallel.

The retrieval device 10 may also include a first support member 26, asecond support member 28, and a third support member 30. The supportmembers 26, 28, and 30 may include lumens 34, 36, and 38 extendinglongitudinally therethrough, respectively. In one embodiment, at leastone of the support members 26, 28, and 30 may be a tube. The supportmembers 26, 28, and 30 may be disposed circumferentially about thelongitudinal axis of the outer sheath 12. The longitudinal axes of thesupport members may be disposed at equal intervals circumferentiallyabout the longitudinal axis. It should, however, be noted that any othersuitable number of support members and spacing configurations mayalternatively be utilized. Each of the support members 26, 28, and 30may have any suitable cross-sectional shape, including cylindricalelliptical, polygonal, and/or irregular. One or more of the supportmembers 26, 28, and 30 may include a portion flattened, machined,extruded, drawn, and/or etched into a different profile than a remainingportion. One or more of the support members 26, 28, and 30 may beslotted to allow deflection or directional bending. One or more of thesupport members 26, 28, and 30 may have an inner diameter of about 0.007inches, a wall thickness of about 0.001 inches, and/or a length of about19.5 millimeters, although other suitable dimensions may alternativelybe utilized. The exterior surfaces of one or more of the support members26, 28, and 30 may be roughened, notched, slotted, etched, sand-blasted,or otherwise modified to provide a better gripping surface. The supportmembers 26, 28, and 30 may be made of any suitable material, including apolymer such as polyimide, or polyethylene terephthalate.

The movable members 18, 20, and 22 and the support members 26, 28, and30 may be heat treated together, and the material for the movablemembers 18, 20, and 22 and the support members 26, 28, and 30 may beselected such that the support members 26, 28, and 30 will not meltduring heat treatment of the movable members 18, 20, and 22. While threesupport members 26, 28, and 30 are shown, one or more additional supportmembers may be used.

Proximal portions of the support members 26, 28, and 30 may extendthrough the lumen 14, and may be covered by the outer sheath 12. Forexample, a length of about 10 millimeters of one or more of the supportmembers 26, 28, and 30 may be covered by the outer sheath 12, leaving alength of about 9.5 millimeters exposed distal to the outer sheath 12.Each of the support members 26, 28, and 30 may contact the other twosupport members. For example, each of the proximal portions of thesupport members 26, 28, and 30 may contact the proximal portions of theother two support members, such that the support members 26, 28, and 30may have a triangular arrangement around the longitudinal axis of theouter sheath 12 as shown in FIGS. 2 and 3. Longitudinal axes of thesupport members 26, 28, and 30 may form vertices of a triangle, andportions of the longitudinal axes may be parallel.

Distal portions of the support members 26, 28, and 30 may extenddistally out of the lumen 14 and away from the distal end of the outersheath 12. The distal portions may be configured to move towards andaway from the longitudinal axis of the outer sheath 12. The number ofsupport members 26, 28, and 30 may be equal to the number of movablemembers 18, 20, and 22.

Each of the three support members 26, 28, and 30 may be coupled to theouter sheath 12. For example, proximal ends of the support members 26,28, and 30 that are covered by the distal end of the outer sheath 12 maybe coupled to the distal end of the outer sheath 12 by an adhesive 13,such as an ultraviolet light curable adhesive or cyanoacrylate.Additionally or alternatively, the distal end of the outer sheath 12 maybe heat shrunk onto the proximal ends of the support members 26, 28, and30. The coupling may keep the proximal ends of the support members 26,28, and 30 stationary relative to the distal end of outer sheath 12,while allowing the distal ends of the support members 26, 28, and 30 tomove relative to the distal end of the outer sheath 12 and relative toone another.

The first leg 18 a may extend distally from the drive member 16, and mayenter the lumen 34 at the proximal end of the first support member 26.The first leg 18 a may extend distally through the lumen 34, and mayexit the lumen 34 at the distal end of the first support member 26.There the first leg 18 a may transition into the bend 18 b. The bend 18b may transition into the second leg 18 c. The second leg 18 c may enterthe lumen 36 at the distal end of the second support member 28. Thesecond leg 18 c may extend proximally through the lumen 36, and may exitthe lumen 36 at the proximal end of the second support member 28.

The first leg 20 a may extend distally from the drive member 16, and mayenter the lumen 36 at the proximal end of the second support member 28.The first leg 20 a may extend distally through the lumen 36, and mayexit the lumen 36 at the distal end of the second support member 28.There the first leg 20 a may transition into the bend 20 b. The bend 20b may transition into the second leg 20 c. The second leg 20 c may enterthe lumen 38 at the distal end of the third support member 30. Thesecond leg 20 c may extend proximally through the lumen 38, and may exitthe lumen 38 at the proximal end of the third support member 30.

The first leg 22 a may extend distally from the drive member 16, and mayenter the lumen 38 at the proximal end of the third support member 30.The first leg 22 a may extend distally through the lumen 38, and mayexit the lumen 38 at the distal end of the third support member 30.There the first leg 22 a may transition into the bend 22 b. The bend 22b may transition into the second leg 22 c. The second leg 22 c may enterthe lumen 34 at the distal end of the first support member 26. Thesecond leg 22 c may extend proximally through the lumen 34, and may exitthe lumen 34 at the proximal end of the first support member 26.

Alternatively, it is contemplated that the first leg 18 a may extenddistally through the first support member 26, and the second leg 18 cmay extend proximally through the third support member 30. The first leg20 a may extend distally through the second support member 28, and thesecond leg 20 c may extend proximally through the first support member26. The first leg 22 a may extend distally through the third supportmember 30, and the second leg 22 c may extend proximally through thesecond support member 28.

Distal ends of the second legs 18 c, 20 c, and 22 c may be coupled by acoupler 46. The coupler 46 may be a tube, and may include a lumen 48configured to receive distal ends of the second legs 18 c, 20 c, and 22c. The second legs 18 c, 20 c, and 22 c may be attached to each otherwithin the coupler 46. One or more of the second legs 18 c, 20 c, and 22c may be attached to the coupler 46. For example, one of more of thesecond legs 18 c, 20 c, and 22 c may be attached to the coupler 46 byadhesive, melting, welding, friction fit, heat-shrinking the coupler 46,and/or any other suitable form of attachment. Portions of the first legs18 a, 20 a, and 22 a may extend along the side of the coupler 46, andmay contact the exterior surface of the coupler 46. The coupler 46 mayspace portions of the first legs 18 a, 20 a, and 22 a apart from thelongitudinal axis of the outer sheath 12, to help guide the first legs18 a, 20 a, and 22 a into the support members 26, 28, and 30.

The movable members 18, 20, and 22, and the support members 26, 28, and30, may form an end effector 50. The end effector 50 may be a basket 52.In FIGS. 1-3, the end effector 50 is shown in a retracted and contractedstate. The end effector 50 may be moved into its retracted andcontracted state by moving the drive member 16 proximally relative tothe outer sheath 12. In the retracted and contracted state, the bends 18b, 20 b, and 22 b may be at or adjacent to the distal ends of thesupport members 26, 28, and 30. Distal ends of the first legs 18 a, 20a, and 22 a and the second legs 18 c, 20 c, and 22 c may be positionedwithin the lumens 34, 36, and 38 of the support members 26, 28, and 30.The longitudinal axes of the support members 26, 28, and 30 may besubstantially parallel, and both proximal and distal portions of each ofthe support members 26, 28, and 30 may be in contact the other supportmembers. Portions of the first legs 18 a, 20 a, and 22 a and the secondlegs 18 c, 20 c, and 22 c in the lumens 34, 36, and 38 may besubstantially parallel. The support members 26, 28, and 30, and/or theouter sheath 12 may counteract the inherent bias in the movable members18, 20, and 22, keeping portions of the movable members 18, 20, and 22from bending radially outwardly from the longitudinal axis of the outersheath 12.

In the retracted and contracted state, the distal end of the coupler 46may be spaced from the proximal ends of the support members 26, 28, and30 by a distance 47. The distance 47 may be about 1 millimeter, althoughother distances may also be used. The proximal end of the coupler 46 maybe spaced from the distal end of the sleeve 24 by a distance including adistance 49 and a distance 51. The distances 49 and 51 may total toabout 16 millimeters, although other distances may also be used. Forexample, the distance 49 may be about 12 to 13 millimeters, while thedistance 51 may be about 3 to 4 millimeters. The distances 47, 49, and51 may vary based on the procedure being performed with the retrievaldevice 10.

In FIGS. 4 and 5, the retrieval device 10 is shown with the end effector50 in an extended and expanded state. In the extended and expandedstate, portions of the movable members 18, 20, and 22 may be exposedfrom the distal ends of the support members 26, 28, and 30 and the outersheath 12. Once exposed, one or more of the movable members 18, 20, and22 may move radially outwardly from the longitudinal axis of the outersheath 12 due to inherent radially outward biasing in one or more of themovable members 18, 20, and 22. Radially outward movement of one or moreof the movable members 18, 20, and 22 may cause a corresponding radiallyoutward movement of the support members 26, 28, and 30.

The exposed portions of the movable members 18, 20, and 22 may formbridges 62, 64, and 66 between the distal ends of the support members26, 28, and 30. Each bridge may extend distally from the distal end of agiven support member, and may be received in the distal end of anadjacent support member. The bridges 62, 64, and 66 may be formed bydistal portions of the first legs 18 a, 20 a, and 22 a, the bends 18 b,20 b, and 22 b, and distal portions of the second legs 18 c, 20 c and 22c.

Each bridge and its corresponding two support members may form a sideloop of the end effector 50. Three side loops 54, 56, and 58 are shownin FIGS. 4 and 5. The bridges 62, 64, and 66 may form a front loop 60 ofthe end effector 50. Materials may enter the end effector 50 through oneor more of the front loop 60 and the side loops 54, 56, and 58. Byadding additional movable members and support members, additional sideloops can be created.

The drive member 16 may be moved distally relative to the outer sheath12 to extend the end effector 50, allowing the end effector 50 to moveto its extended and expanded state due to inherent radially outwardbiasing in one or more of the movable members 18, 20, and 22. Extensionand expansion of the end effector 50 may occur in phases. Starting fromthe retracted and contracted state shown in FIG. 1, a first phase of theextension and expansion of the end effector 50 may begin with movementof the drive member 16 distally relative to the outer sheath 12 and thesupport members 26, 28, and 30. The relative movement of the drivemember 16 may cause the movable members 18, 20, and 22 and the coupler46 to move distally relative to the outer sheath 12. The movement of thedrive member 16, movable members 18, 20, and 22, and coupler 46 may betranslational. For example, the drive member 16, first legs 18 a, 20 a,and 22 a, bends 18 b, 20 b, and 22 b, second legs 18 c, 20 c, and 22 c,and coupler 46, may move distally relative to the outer sheath 12 andsupport members 26, 28, and 30 during the first phase. Proximal portionsof the first legs 18 a, 20 a, and 22 a and second legs 18 c, 20 c, and22 c may enter the lumens 34, 36, and 38 of the support members 26, 28,and 30 at the proximal ends of the support members 26, 28, and 30.Distal portions of the first legs 18 a, 20 a, and 22 a, bends 18 b, 20b, and 22 b, and second legs 18 c, 20 c, and 22 c may emerge from, orextend further out from, the distal ends of the support members 26, 28,and 30. The exposed portions of the movable members 18, 20, and 22 mayform the bridges 62, 64, and 66, and the lengths of the bridges 62, 64,and 66 may grow as the exposed lengths of the movable members 18, 20,and 22 grow. As the bridges 62, 64, and 66 grow, distal portions of themovable members 18, 20, and 22, and the support members 26, 28, and 30,may expand radially outwardly from the longitudinal axis of the outersheath 22. The front loop 60 and side loops 54, 56, and 58 may grow insize.

The coupler 46 may move with the movable members 18, 20, and 22 relativeto the outer sheath 12 and support members 26, 28, and 30. When thecoupler 46 has traveled the distance 47 relative to the outer sheath 12and support members 26, 28, and 30, further distal movement of thecoupler 46 may be halted as the coupler 46 reaches a point where itprevents further spreading of the second legs 18 c, 20 c, and 22 c, thuspreventing the second legs 18 c, 20 c, and 22 c from entering the lumens34, 36, and 38 of the support members 26, 28, and 30. At the end of thefirst phase of extension and expansion, the bends 18 b, 20 b, and 22 bmay each be spaced from distal ends of the support members 26, 28, and30 by the distance 47.

A second phase of the extension and expansion of the end effector 50 maybegin after distal movement of the coupler 46 has been halted. Duringthe second phase, further distal movement of the drive member 16relative to the outer sheath 12 and support members 26, 28, and 30 maydrive distal movement of the first legs 18 a, 20 a, and 22 a relative tothe outer sheath 12 and support members 26, 28, and 30. During thesecond phase, the second legs 18 c, 20 c, and 22 c may remain fixedrelative to the support members 26, 28, and 30. The first legs 18 a, 20a, and 22 a may be increasingly exposed from the distal ends of thesupport members 26, 28, and 30, thereby increasing the lengths of thebridges 62, 64, and 66. Distal portions of the movable members 18, 20,and 22, and the support members 26, 28, and 30, may expand radiallyoutwardly. The front loop 60 and the side loops 54, 56, and 58 may alsoexpand in size.

Extension and expansion in the second phase may continue over thedistance 49. Once the first legs 18 a, 20 a, and 22 a have traveled thedistance 49, distal movement of the drive member 16 may halt. Distalmovement of the drive member 16 may be halted where the distal end ofthe sleeve 24 prevents the first legs 18 a, 20 a, and 22 a fromspreading far enough apart to enter the proximal ends of the supportmembers 26, 28, and 30. Additionally or alternatively, distal movementmay halt due to operation of a handle assembly of the retrieval device10, such as a handle assembly 200 described further below.

Moving the end effector 50 back to the retracted and contracted statemay be accomplished by moving the drive member 16 proximally relative tothe outer sheath 12 and support members 26, 28, and 30. Movement fromthe extended and expanded state to the retracted and contracted statemay also occur in phases. A first phase of the retraction andcontraction of the end effector 50 may begin with the drive member 16moving proximally relative to the outer sheath 12. This may cause thefirst legs 18 a, 20 a, and 22 a to move proximally relative to the outersheath 12 and support members 26, 28, and 30. Distal portions of thefirst legs 18 a, 20 a, and 22 a may enter the lumens 34, 36, and 38 atthe distal ends of the support members 26, 28 and 30. The second legs 18c, 20 c, and 22 c, and the coupler 46 may remain stationary relative tothe support members 26, 28, and 30. The lengths of the bridges 62, 64,and 66 may decrease. The first legs 18 a, 20 a, and 20 a, second legs 18c, 20 c, and 22 c, and support members 26, 28, and 30 may move radiallyinwardly. Thus, the front loop 60 and the side loops 54, 56, and 58 maydecrease in size.

The first phase of the retraction and contraction of the end effector 50may take place over the distance 49. Once the distance 49 has beencovered, a second phase of the retraction and contraction may take placewith continued movement of the drive member 16 proximally relative tothe outer sheath 12 and the support members 26, 28, and 30. Thecontinued movement may cause the movable members 18, 20, and 22 and thecoupler 46 to move distally relative to the outer sheath 12 and supportmembers 26, 28, and 30. The movement of the drive member 16, movablemembers 18, 20, and 22, and coupler 46 may be translational. Forexample, the drive member 16, first legs 18 a, 20 a, and 22 a, bends 18b, 20 b, and 22 b, second legs 18 c, 20 c, and 22 c, and coupler 46, maymove proximally relative to the outer sheath 12 and support members 26,28, and 30 during the second phase. Proximal portions of the first legs18 a, 20 a, and 22 a and second legs 18 c, 20 c, and 22 c may exit thelumens 34, 36, and 38 of the support members 26, 28, and 30 at theproximal ends of the support members 26, 28, and 30. Distal portions ofthe first legs 18 a, 20 a, and 22 a, bends 18 b, 20 b, and 22 b, andsecond legs 18 c, 20 c, and 22 c may enter into, or move further past,the distal ends of the support members 26, 28, and 30. The lengths ofthe bridges 62, 64, and 66 may decrease as the exposed lengths of themovable members 18, 20, and 22 decrease. As the bridges 62, 64, and 66shrink, distal portions of the movable members 18, 20, and 22, and thesupport members 26, 28, and 30, may contract radially inwardly towardthe longitudinal axis of the outer sheath 22. The front loop 60 and sideloops 54, 56, and 58 may also shrink in size.

The coupler 46 may move with the movable members 18, 20, and 22 relativeto the outer sheath 12 and support members 26, 28, and 30. When thecoupler 46 has traveled the distance 47 relative to the outer sheath 12and support members 26, 28, and 30, further proximal movement of thecoupler 46 may be halted as the bends 18 b, 20 b, and 22 b reach a pointwhere they prevent further proximal movement of the movable members 18,20, and 22. Additionally or alternatively, further movement may behalted by operation of a handle assembly of the retrieval device 10,such as the handle assembly 200 described further below. At the end ofthe second phase of retraction and contraction, the state shown in FIG.1 is attained.

As shown in FIG. 7, the drive member 16 may be rotated about itslongitudinal axis. Rotation 68 of the drive member 16 may twist themovable members 18, 20, and 22, causing portions of the first legs 18 a,20 a, and 22 a to form into a twisted section 70. In the twisted section70, the movable members 18, 20, and 22 may follow a helical path.Continued rotation of the drive member 16 in the first direction mayincrease the twist. Rotating the drive member 16 in a second direction,opposite the first direction, may decrease the twist. FIG. 1 shows thedevice 10 without any twisting. Rotating the drive member 16 may alsocause torsion or twisting 72 in each of the movable members 18, 20, and22 about their respective longitudinal axes. Continued rotation of thedrive member 16 in the first direction may cause the torsion or twisting72 to increase. Rotating the drive member 16 in the second direction maycause the torsion or twisting 72 to decrease. The bends 18 b, 20 b, and22 b and the second legs 18 c, 20 c, and 22 c may not become twisted dueto their engagement with the support members 26, 28, and 30 and/or thecoupler 46. The twisting and/or torsion may enhance or increase theinherent radially outward bias present in the movable members 18, 20,and 22.

As shown in FIG. 6, due to the rotation 68 of the drive member 16,characteristics of the extended and expanded end effector 50 may change.For example, due to the twisting of and/or torsion in the movablemembers 18, 20, and 22, when extended distally the movable members 18,20, and 22 may expand radially outwardly from the longitudinal axis ofthe outer sheath 12 farther than they would with less of or without thetwisting and/or torsion. As a result, with the end effector 50 extendedand expanded and subject to twisting and/or torsion, the length of aradial line 74 extending from the longitudinal axis of the outer sheath12 to the outermost point on any of the bridges 62, 64, and 66 in FIG. 6may be greater than the length of a radial line 76 extending from thelongitudinal axis of the outer sheath 12 to the outermost point on anyof the bridges 62, 64, and 66 in FIG. 5 corresponding to the endeffector 50 where the movable members 18, 20, and 22 are not subject totwisting and/or torsion. The perimeter of the front loop 60 in FIG. 6may be greater than the perimeter of the front loop 60 in FIG. 5. Theperimeters of the side loops 54, 56, and 58 in FIG. 6 may be greaterthan the perimeters of the side loops in FIG. 5.

Further, due to the twisting of and/or torsion in movable members 18,20, and 22, the angle formed between portions of the movable members 18,20, and 22 within the distal ends of the support members 26, 28, and 30and the longitudinal axis of the outer sheath 12, when the basket isextended and expanded, may be greater than they would be with less of orwithout the twisting and/or torsion. Similarly, the angle formed betweeneach of the distal ends of the support members 26, 28, and 30, and thelongitudinal axis of the outer sheath 12, may be greater than it wouldbe with less of or without the twisting and/or torsion.

Further, due to the twisting of and/or torsion in the movable members18, 20, and 22, the end effector 50 in FIG. 6 may expand radiallyoutwardly farther over less of an extension distance than the endeffector 50 in FIGS. 4 and 5. For example, with reference to FIG. 4,when the movable members 18, 20, and 22 are twisted, the end effector 50may reach full radial expansion at a first distance 78 from the distalend of the outer sheath 12. With less of or without the twisting and/ortorsion, the end effector 50 may reach full radial expansion whenextended a second distance 80 from the distal end of the outer sheath12. The first distance 78 may be less than the second distance 80.Because the end effector 50 in FIG. 6 expands over a shorter distance,it may have the ability to grab bigger objects/more material earlier inits extension phase, and do so more securely because the movable members18, 20, and 22 tend to lose strength the further out they are extended.As such, at full extension and expansion, the end effector 50 in FIG. 6may be stronger than the end effector 50 in FIGS. 4 and 5. Shortersupport members 26, 28, and 30 may be used for the basket in FIG. 6 thanfor the basket in FIGS. 4 and 5. A support member that is shorter isstronger than an support member that is longer. Shortening the supportmembers 26, 28, and 30 may further strengthen the end effector 50 inFIG. 6. Accordingly, the user may be provided with enhanced control overthe end effector 50 in FIG. 6 since it will better resist deformationunder stress than the end effector 50 in FIGS. 4 and 5.

Further, since the end effector 50 in FIG. 6 fully expands over ashorter distance than the end effector 50 in FIGS. 4 and 5, a user maybe able to index distances and/or sizes of objects in the target areabecause visualization aids at or near the distal end of the outer sheath12 may be closer to the end effector 50 when it is extended andexpanded. Furthermore, because the end effector 50 in FIG. 6 fullyexpands over a shorter distance, the end effector 50 in FIG. 6 may alsocontract over a shorter distance. Thus, the end effector 50 in FIG. 6may be closed down on an object or material being retrieved faster thanthe end effector 50 in FIGS. 4 and 5. This may also provide the userwith better control over the end effector 50, and/or the object ormaterial.

It is contemplated that 1-2 rotations of the drive member 16 may besufficient for creating the end effector 50 in FIG. 6, although it ispossible that the number of rotations/partial rotations may vary basedon properties of device components (e.g., movable membercharacteristics, support member characteristics, outer sheathcharacteristics, etc.). Rotation of the drive member 16 may also beadjustable based on how much basket expansion a user wants at one ormore points during basket extension. Too much rotation may twist themovable members 18, 20, and 22 to a degree that prevents portions of thefirst legs 18 a, 20 a, and 22 a from separating and entering theproximal ends of the support members 26, 28, and 30.

The direction of rotation of the drive member 16 that may enhance basketexpansion may depend on the arrangement of the movable members 18, 20,and 22 in the support members 26, 28, and 30. For example, when thefirst leg 18 a extends distally through the first support member 26, thesecond leg 18 c extends proximally through the second support member 28,the first leg 20 a extends distally through the second support member28, the second leg 20 c extends proximally through the third supportmember 30, the first leg 22 a extends distally through the third supportmember 30, and the second leg 22 c extends proximally through the firstsupport member 26, rotating the drive member 16 in a first direction mayincrease twisting of the movable members 18, 20, and 22, and mayincrease torsion within the movable members 18, 20, and 22, causing theend effector 50 to expand in the manner shown in FIG. 6. Rotating thedrive member 16 in a second direction (opposite the first direction) maynot have that effect on expansion of the end effector 50.

On the other hand, when the first leg 18 a extends distally through thefirst support member 26, the second leg 18 c extends proximally throughthe third support member 30, the first leg 20 a extends distally throughthe second support member 28, the second leg 18 c extends proximallythrough the first support member 26, the first leg 22 a extends distallythrough the third support member 30, and the second leg 22 c extendsproximally through the second support member 28, rotating the drivemember 16 in the second direction may increase twisting of the movablemembers 18, 20, and 22, and may increase torsion in the movable members18, 20, and 22, causing the end effector 50 to expand in the mannershown in FIG. 6. Rotating the drive member 16 in the first direction maynot have that effect on expansion of the end effector 50.

FIGS. 8A-8D show the handle assembly 200. The handle assembly 200 mayinclude a housing 202, an actuation assembly 204, a holding mechanism216, and an end cap 206. The actuation assembly 204 (FIG. 8D) mayinclude a body 208, and a protrusion 210 on an upper surface the body208. The actuation assembly 204 may be at least partially received in apassage or cavity 212 of the housing 202. The cavity 212 may open into alongitudinal slot 222 running along an outer surface of the housing 202.The actuation assembly 204 may be slidable relative to the housing 202within the cavity 212. For example, a user may grip the housing 202 inthe palm of his/her hand, and may place his/her thumb on the protrusion210. The user may push the actuation assembly 204 distally relative tothe housing 202 by pushing the protrusion 210 with his/her thumb in adistal direction. The user may push the actuation assembly 204proximally relative to the housing 202 by pushing the protrusion 210with his/her thumb in a proximal direction.

A distal portion of the actuation assembly 204 may extend distally fromthe distal end of the housing 202. For example, the distal portion mayextend out of an opening (not shown) at the distal end of the cavity212. The distal portion may include a connector 214 configured toconnect the outer sheath 12 to the body 208. The connector 214 mayinclude, for example, a strain relief member. The outer sheath 12 may bemoved distally relative to the drive member 16 (and the movable members18, 20, and 22) by moving the actuation assembly 204 distally, andproximally by moving the actuation assembly 204 proximally.

The proximal end of the drive member 16 may extend through the handleassembly 200. The drive member 16 may extend through the cavity 212 orany other suitable opening or openings in the housing 202 and/or theactuation assembly 204. The housing 202 may receive a holding mechanism216 (FIG. 8C). A proximal end of the holding mechanism 216 may include avise, or any other suitable holding mechanism, that may extendproximally from the proximal end of the housing 202. The holdingmechanism 216 may include a first jaw member 218 and a second jaw member220. When the first and second jaw members 218 and 220 move toward oneanother, they may hold/clamp the drive member 16 between them, thuscoupling the drive member 16 to the holding mechanism 216, and to thehousing 202. The end cap 206 may help close the first and second jawmembers 218 and 220 around the drive member 16 when the end cap 206 isplaced over the proximal end of the housing 202. For example, thehousing 202 may include an externally threaded portion 227. The end cap206 may include complementary internal threading (not shown), and may bescrewed onto the housing 202.

When the outer sheath 12 is moved distally by moving the actuationassembly 204 distally, the outer sheath 12 and support members 26, 28,and 30 may move distally relative to the housing 202, the drive member16, and movable members 18, 20, and 22. The distally moving supportmembers 26, 28, and 30 may slide over portions of the movable members18, 20, and 22 forming the end effector 50, putting the end effector 50in its retracted and contracted state. Moving the outer sheath 12proximally by moving the actuation assembly 204 proximally may move theouter sheath 12 and support members 26, 28, and 30 proximally relativeto the housing 202, the drive member 16, and movable members 18, 20, and22. The proximally moving support members 26, 28, and 30 may slide offof or expose the portions of the movable members 18, 20, and 22 formingthe end effector 50, allowing the end effector 50 to move to itsextended and expanded state.

The amount of relative movement between the outer sheath 12 and supportmembers 26, 28, and 30; and the drive member 16 and movable members 18,20, and 22, may be set by engagement between portions of the actuationassembly 204 and the holding mechanism 216. For example, the holdingmechanism 216 may include a proximal wall or protrusion 231 and a distalwall or protrusion 225. A proximal wall or protrusion 229 of theactuation assembly 204 may move proximally and distally in the spacebetween the protrusions 225 and 231.

In one embodiment of the retrieval device 10, the end effector 50 may bein its retracted and contracted state (FIGS. 1-3) when the protrusion229 of the actuation assembly 204 engages the protrusion 225 of theholding mechanism 216. The actuation assembly 204 move be movedproximally relative to the holding mechanism 216 and the housing 202,thus moving the outer sheath 12 and support members 26, 28, and 30proximally relative to the drive member 16 and movable members 18, 20,and 22, and moving the end effector 50 into its extended and expandedstate (FIGS. 4-6). Proximal movement of the actuation assembly 204relative to the holding mechanism 216 and the housing 202 may halt whenthe protrusion 229 contacts the protrusion 231 of the holding mechanism216. During this movement, the distance moved by the protrusion 229, inthe space between protrusions 225 and 231, may produce distal movementof the first legs 18 a, 20 a, and 22 a relative to the outer sheath 12and support members 26, 28, and 30 over a distance including distances49 and 51. The actuation assembly 204 may be moved distally relative tothe holding mechanism 216 and the housing 202, until the protrusion 229contacts the protrusion 225, to move the end effector 50 back into itsretracted and contracted state. It is also contemplated that engagementbetween the protrusions 225 and 229 may help prevent the distal ends ofthe support members 26, 28, and 30 from being forced against the bends18 b, 20 b, and 22 b of the movable members 18, 20, and 22, duringretraction/contraction of the end effector 50. Excessive force betweenthe distal ends of the support members 26, 28, and 30 and the bends 18b, 28 b, and 22 b may cause splitting of the support members 26, 28, and30.

In another embodiment of the retrieval device 10, the actuation assembly204 may include a limiter 223 for limiting movement between theactuation assembly 204 and the holding mechanism 216. The limiter 223may include, for example, a tube coupled to a distal face of theprotrusion 229 of the actuation assembly 204. The end effector 50 may bein its retracted and contracted state (FIGS. 1-3) when the distal end ofthe limiter 223 engages the protrusion 225 of the holding mechanism 216.The actuation assembly 204 move be moved proximally relative to theholding mechanism 216 and the housing 202, thus moving the outer sheath12 and support members 26, 28, and 30 proximally relative to the drivemember 16 and movable members 18, 20, and 22, and moving the endeffector 50 into its extended and expanded state (FIGS. 4-6). Proximalmovement of the actuation assembly 204 relative to the holding mechanism216 and the housing 202 may halt when the protrusion 229 contacts theprotrusion 231 of the holding mechanism 216. During this movement, thedistance covered by the protrusion 229 may be less than the distancecovered by the protrusion 229 in the absence of the limiter 223, due tothe length of the limiter 223 prepositioning the protrusion 229 fartherproximally relative to the protrusion 225. The shortened distance mayresult in the distal movement of the first legs 18 a, 20 a, and 22 arelative to the outer sheath 12 and support members 26, 28, and 30 overthe distance 49, leaving the distance 51 unused. The actuation assembly204 may be moved distally relative to the holding mechanism 216 and thehousing 202, until the limiter 223 contacts the protrusion 225, to movethe end effector 50 back into its retracted and contracted state.

In the embodiment that includes the limiter 223, only the distance 49 isnormally used during extension/expansion and/or retraction/contractionof the end effector 50. If, however, an object captured in the endeffector 50 is too large to be released from the end effector 50 bynormal extension/expansion of the end effector 50, the user can removethe end cap 206 to free the drive member 216 from the holding mechanism216. The user may then manipulate the drive member 216 manually in adistal direction relative to the actuation assembly 204, outer sheath12, and support members 26, 28, and 30, over the distance 51, allowingfor additional extension/expansion of the end effector 50 for releasingthe object. Thus the limiter 223 and the distance 51 may provide anescape length of additional travel to help ensure that objects that maybe small enough to be captured in the end effector 50, but too large tobe readily removed from the end effector 50, may still be released. Itis also contemplated that the engagement between the limiter 223 and theprotrusion 226 may help prevent the distal ends of the support members26, 28, and 30 from being forced against the bends 18 b, 20 b, and 22 bof the movable members 18, 20, and 22. Excessive force between the bends18 b, 20 b, and 22 b and the distal ends of the support members 26, 28,and 30 may result in splitting of the support members 26, 28, and 30during retraction/contraction of the end effector 50.

It is contemplated that the rotation 68 (FIGS. 6 and 7) may be appliedto the drive member 16 by removing the end cap 206, taking hold of theproximal end of the drive member 16, rotating the drive member 16 in adesired direction through a desired rotation angle, and then closing theholding mechanism 216 around the rotated drive member 16 to keep thedrive member 16 in its rotated state. The rotation 68 may provide thetwist and/or torsion to the movable members 18, 20, and 22, so that theend effector 50 may be extended and expanded as shown in FIG. 6. Therotation 68 may be applied to the drive member 16 during manufacturing,such that the device may have a predetermined amount of rotation when itis received by a user.

FIG. 9 shows another embodiment of a handle assembly 300. The handleassembly 300 may include a housing 302 and an actuation assembly 304.The actuation assembly 304 may include a body 308, and an actuationmember 310 on the body 308. The actuation member 310 may include aprotrusion 312 and a ring 314. The ring 314 may be received in acircumferentially extending slot 318 of the body 308. The body 308 andthe ring 314 may be relatively rotatable. Relative longitudinal movementbetween the body 308 and the ring 314 may be limited or prevented due toengagement between proximal and distal surfaces of the ring 314 andproximal and distal surfaces of the slot 318.

The actuation assembly 304 may be slidably received in a lumen 306 ofthe housing 302. The protrusion 312 may be slidably received in alongitudinal slot 316 running along an upper surface of the housing 302.The actuation assembly 304 may be slidable relative to the housing 302within the lumen 306. For example, a user may grip the housing in thepalm of his/her hand, and may place his/her thumb on the protrusion 312.The user may push the actuation assembly 304 distally relative to thehousing 302 by pushing the protrusion 312 with his/her thumb in a distaldirection. The user may push the actuation assembly 304 proximallyrelative to the housing 302 by pushing the protrusion 312 with his/herthumb in a proximal direction.

The body 308 may include a keyway or slot 320 running along its length.The slot 320 may be in the shape of a spiral or helix. A key orprotrusion 322 may extend radially inwardly from the interior surface ofthe housing 302. As the actuation assembly 304 moves proximally ordistally, the key 322 may engage the slot 320, causing the body 308 torotate. The actuation member 310 may be configured to not rotate withthe body 308, due to the ring 314 being connected to, but freelyrotatable relative to the body 308.

The distal end of the housing 302 may be coupled to the proximal end ofthe outer sheath 12. The proximal end of the drive member 16 may becoupled to the distal end of the body 308. Thus, the drive member 16 maybe moved distally by moving the actuation assembly 304 distally, andproximally by moving the actuation assembly 304 proximally. The rotation68 (FIGS. 6 and 7) on the drive member 16 may be applied to and/orincreased by the rotation of the body 308 through engagement between thekey 322 and the keyway 320 during distal movement of the actuationassembly 304. The rotation 68 may be decreased and/or removed from thedrive member 16 by rotation of the body 308 through engagement betweenthe key 322 and the slot 320 during proximal movement of the actuationassembly 304. With the embodiment in FIG. 9, the rotation 68 may beapplied and/or increased while extending and expanding the end effector50, and decreased and/or removed while retracting and contracting theend effector 50. It is contemplated that the orientation of the slot 320(e.g., the direction of the spiral or helix) may be reversed to reversethe directions of rotation of the body 308 during proximal and distalmovements of the actuation assembly 304. It is also contemplated thatthe amount of rotation 68 of the drive member 16 may be controlled bycontrolling the characteristics of the slot 320, such as the distancebetween its turns.

It is contemplated that the actuation assembly 304 may be coupled to thehousing 302 by a mechanical fastening mechanism (not shown). Thefastening mechanism may help keep the actuation assembly 304 in aposition relative to the housing 302 when the actuation assembly 304 isnot being moved by a user. The fastening mechanism may include, forexample, friction fit engagement, a ratchet assembly, a latchingassembly, or any other suitable fastening mechanism. Further, it iscontemplated that in some embodiments, the fastening mechanism may actbetween the housing 302 and at least one of the body 308 and theactuation member 310.

FIG. 10 shows another embodiment of a handle assembly 400. The handleassembly 400 may include a housing 402 and an actuation assembly 404.The actuation assembly 404 may include a body 408, and an actuationmember 410 on the body 408. The actuation member 410 may include aprotrusion 412 and a ring 414. The ring 414 may be received in acircumferentially extending slot 416 of the body 408. The body 408 andthe ring 414 may be relatively rotatable. Relative longitudinal movementbetween the body 408 and the ring 414 may be limited due to engagementbetween proximal and distal surfaces of the ring 414 and proximal anddistal surfaces of the slot 416.

The actuation assembly 404 may be received in a lumen 406 of the housing402. The protrusion 412 may be received in a longitudinal slot 418running along an upper surface of the housing 402. The actuationassembly 404 may be slidable relative to the housing 402 within thelumen 406. For example, a user may grip the housing in the palm ofhis/her hand, and may place his/her thumb on the protrusion 412. Theuser may push the actuation assembly 404 distally relative to thehousing 402 by pushing the protrusion 412 with his/her thumb in a distaldirection. The user may push the actuation assembly 404 proximallyrelative to the housing 402 by pushing the protrusion 412 with his/herthumb in a proximal direction.

The proximal end of the body 408 may extend proximally out of thehousing 402. A user may grasp the proximal end of the body 408 androtate the body 408 in clockwise and counterclockwise directions. Theactuation member 410 may remain circumferentially set during rotation ofthe body 408, due to the ring 414 being freely rotatable relative to thebody 408, and due to engagement between the actuation member 410 and thesides of the longitudinal slot 418.

The distal end of the housing 402 may be coupled to the proximal end ofthe outer sheath 12. The proximal end of the drive member 16 may becoupled to the distal end of the body 408. Thus, the drive member 16 maybe moved distally by moving the actuation assembly 404 distally, andproximally by moving the actuation assembly 404 proximally. The rotation68 (FIGS. 6 and 7) of the drive member 16 may be applied and/orincreased by the user rotating the proximal end of the body 408 on onedirection. The rotation 68 may provide the movable members 18, 20, and22 with the twist and/or torsion for expanding the end effector 50 tothe state shown in FIG. 6. The rotation 68 may be decreased and/orremoved from the drive member 16 by the user rotating the proximal endof the body 408 in the opposite direction. With the embodiment in FIG.10, the rotation 68 may be increased before, during, or after extendingand retracting the end effector 50. It is contemplated that the body 408may be selectively held in place by any suitable mechanical fasteningmechanism, such as a friction fit assembly, ratchet assembly, orlatching assembly.

The disclosed retrieval devices may be utilized in any suitableapplication requiring the capture and removal of materials from thebody. Any aspect set forth in any embodiment may be used with any otherembodiment set forth herein. The devices may be used in any suitablemedical procedure, may be advanced through any suitable body lumen andbody cavity, and may be used to remove material from any suitable bodyportion. For example, the devices described herein may be used throughany natural body lumen or tract, including those accessed orally,vaginally, rectally, nasally, urethrally, or through incisions in anysuitable tissue.

The disclosed devices may be configured to capture fragments havingdimensions of about 3 French or smaller. In some embodiments, thedisclosed medical devices may be able to capture and release smallerstones having diameters from 1 millimeter to 12 millimeters. In someembodiments, a user may want to reposition larger stones from the lowercalyx to the upper calyx of the kidney to be broken with a laser beforeremoving them through a small diameter of the ureter. The stones may beremoved in front of a scope, as opposed to through scope channel toprevent damage to a scope channel. When stones are removed, both anendoscope and the retrieval device may be removed from the human body.In some embodiments, a guide sheath for a ureteroscope may be used toguide the ureteroscope and retrieval device back to a previous positionor to a new position to capture additional stones, and protect a ureterwall during stone removal. While moving from the extended and expandedstate to the retracted and contracted state, retrieval devices of thepresent disclosure may ligate larger stones and capture smaller stoneswithin the end effector 50.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the disclosed systems andprocesses without departing from the scope of the disclosure. Otherembodiments of the disclosure will be apparent to those skilled in theart from consideration of the specification and practice of the featuresdisclosed herein. It is intended that the specification and examples beconsidered as exemplary only.

We claim:
 1. A retrieval device, comprising: a distally located endeffector movable between a contracted state and an expanded state, theend effector including: a plurality of support members each including apassage, and a plurality of movable members including a first movablemember having a first portion extending into a first passage of thesupport member passages; and a proximally located handle assemblyincluding a longitudinal actuator and a twisting actuator coupled to theplurality of movable members and configured to longitudinally move andtwist the movable members without longitudinally moving and twisting thesupport members.
 2. The retrieval device of claim 1, wherein a secondportion of the first movable member extends out of the first passage andinto a second passage of the support member passages.
 3. The retrievaldevice of claim 1, wherein the first movable member and a pair ofadjacent support members form an end effector loop.
 4. The retrievaldevice of claim 1, wherein the longitudinal actuator and the twistingactuator include a common actuator member for causing longitudinalmoving and twisting of the movable members.
 5. The retrieval device ofclaim 1, wherein a portion of one of the movable members twists around aportion of another of the movable members.
 6. The retrieval device ofclaim 1, wherein a portion of each of the movable members follows ahelical path.
 7. A retrieval device, comprising: a distally located endeffector movable between a contracted state and an expanded state, theend effector including: a plurality of support members each including apassage, and a plurality of movable members at least partially receivedin the passages, wherein, in the expanded state, the movable members aredisplaced longitudinally and twisted relative to the contracted state.8. The retrieval device of claim 7, wherein each of the movable membersincludes a proximal portion and a distal portion, wherein at least partof the proximal portion is rotatable relative to at least part of thedistal portion to generate torsion in the movable member when themovable member is twisted, and the movable members are movablelongitudinally relative to the support members.
 9. The retrieval deviceof claim 8, wherein the torsion in the movable members biases the distalportions of the movable members towards bent configurations.
 10. Theretrieval device of claim 9, further including a sheath configured toreceive the support members and the movable members, wherein each of themovable members extends radially outwardly from a longitudinal axis ofthe retrieval device when in the bent configuration.
 11. The retrievaldevice of claim 7, further including a proximally located handleassembly configured to twist the movable members and move the movablemembers longitudinally relative to the support members.
 12. Theretrieval device of claim 11, wherein the handle assembly is configuredto rotate the movable members while moving the movable memberslongitudinally.
 13. The retrieval device of claim 7, wherein the supportmembers and the movable members form a plurality of loops.
 14. Theretrieval device of claim 13, wherein the plurality of loops include adistal front loop and a plurality of proximal side loops.
 15. A methodfor retrieving an object from a target area, comprising: positioning adistally located end effector of a retrieval device at the target areawith the distally located end effector in a contracted state, the endeffector including: a plurality of support members each including apassage, and a plurality of movable members extending into the supportmember passages; and expanding the end effector by longitudinallyextending and twisting the movable members without longitudinallyextending and twisting the support members, to allow the object to enterthe end effector.
 16. The method of claim 15, wherein the movablemembers are twisted before being longitudinally extended.
 17. The methodof claim 15, wherein the movable members are twisted after beinglongitudinally extended.
 18. The method of claim 15, wherein the movablemembers are twisted while being longitudinally extended.
 19. The methodof claim 15, further including contracting the end effector bylongitudinally retracting the end effector.
 20. The method of claim 19,further including contracting the end effector by untwisting the movablemembers.